A universal model for spike-frequency adaptation

Spike-frequency adaptation is a prominent feature of neural dynamics. Among other mechanisms, various ionic currents modulating spike generation cause this type of neural adaptation. Prominent examples are voltage-gated potassium currents (M-type currents), the interplay of calcium currents and intracellular calcium dynamics with calcium-gated potassium channels (AHP-type currents), and the slow recovery from inactivation of the fast sodium current. While recent modeling studies have focused on the effects of specific adaptation currents, we derive a universal model for the firing-frequency dynamics of an adapting neuron that is independent of the specific adaptation process and spike generator. The model is completely defined by the neuron's onset f-I curve, the steady-state f-I curve, and the time constant of adaptation. For a specific neuron, these parameters can be easily determined from electrophysiological measurements without any pharmacological manipulations. At the same time, the simplicity of the model allows one to analyze mathematically how adaptation influences signal processing on the single-neuron level. In particular, we elucidate the specific nature of high-pass filter properties caused by spike-frequency adaptation. The model is limited to firing frequencies higher than the reciprocal adaptation time constant and to moderate fluctuations of the adaptation and the input current. As an extension of the model, we introduce a framework for combining an arbitrary spike generator with a generalized adaptation current

Artistic Scene Visualization

Cílem této práce je prostudovat vybrané metody nerealistikého uměleckého zobrazení (cell shading, pencil sketch shading, watercolor shading) a napodobit dané techniky při vykreslování objektů ve 3D prostoru s použitím knihovny OpenGL. Oblastí využití těchto technik je široké - od grafických aplikací, přes počítačové hry až po animované filmy. Tato práce popisuje návrh a implementaci těchto technik: cell shading, skica tvořená tužkou a akvarelová malba.The goal of this work is studying of selected artistic scene visualization (cell shading, pencil sketch shading) and simulate these techniques in the rendering of objects in 3D space using OpenGL. Applications of these methods is wide - from graphical application, through computer games to animated films. This work describes design and implementation of these methods: cell shading, pencil sketch shading and watercolor shading.

A Bottom-up Approach to Data Annotation in Neurophysiology

Metadata providing information about the stimulus, data acquisition, and experimental conditions are indispensable for the analysis and management of experimental data within a lab. However, only rarely are metadata available in a structured, comprehensive, and machine-readable form. This poses a severe problem for finding and retrieving data, both in the laboratory and on the various emerging public data bases. Here, we propose a simple format, the “open metaData Markup Language” (odML), for collecting and exchanging metadata in an automated, computer-based fashion. In odML arbitrary metadata information is stored as extended key–value pairs in a hierarchical structure. Central to odML is a clear separation of format and content, i.e., neither keys nor values are defined by the format. This makes odML flexible enough for storing all available metadata instantly without the necessity to submit new keys to an ontology or controlled terminology. Common standard keys can be defined in odML-terminologies for guaranteeing interoperability. We started to define such terminologies for neurophysiological data, but aim at a community driven extension and refinement of the proposed definitions. By customized terminologies that map to these standard terminologies, metadata can be named and organized as required or preferred without softening the standard. Together with the respective libraries provided for common programming languages, the odML format can be integrated into the laboratory workflow, facilitating automated collection of metadata information where it becomes available. The flexibility of odML also encourages a community driven collection and definition of terms used for annotating data in the neurosciences

Energy integration describes sound-intensity coding in an insect auditory system

We investigate the transduction of sound stimuli into neural responses and focus on locust auditory receptor cells. As in other mechanosensory model systems, these neurons integrate acoustic inputs over a fairly broad frequency range. To test three alternative hypotheses about the nature of this spectral integration (amplitude, energy, pressure), we perform intracellular recordings while stimulating with superpositions of pure tones. On the basis of online data analysis and automatic feedback to the stimulus generator, we systematically explore regions in stimulus space that lead to the same level of neural activity. Focusing on such iso-firing-rate regions allows for a rigorous quantitative comparison of the electrophysiological data with predictions from the three hypotheses that is independent of nonlinearities induced by the spike dynamics. We find that the dependence of the firing rates of the receptors on the composition of the frequency spectrum can be well described by an energy-integrator model. This result holds at stimulus onset as well as for the steady-state response, including the case in which adaptation effects depend on the stimulus spectrum. Predictions of the model for the responses to bandpass-filtered noise stimuli are verified accurately. Together, our data suggest that the sound-intensity coding of the receptors can be understood as a three-step process, composed of a linear filter, a summation of the energy contributions in the frequency domain, and a firing-rate encoding of the resulting effective sound intensity. These findings set quantitative constraints for future biophysical models

Timescale-invariant representation of acoustic communication signals by a bursting neuron

Acoustic communication often involves complex sound motifs in which the relative durations of individual elements, but not their absolute durations, convey meaning. Decoding such signals requires an explicit or implicit calculation of the ratios between time intervals. Using grasshopper communication as a model, we demonstrate how this seemingly difficult computation can be solved in real time by a small set of auditory neurons. One of these cells, an ascending interneuron, generates bursts of action potentials in response to the rhythmic syllable-pause structure of grasshopper calls. Our data show that these bursts are preferentially triggered at syllable onset; the number of spikes within the burst is linearly correlated with the duration of the preceding pause. Integrating the number of spikes over a fixed time window therefore leads to a total spike count that reflects the characteristic syllable-to-pause ratio of the species while being invariant to playing back the call faster or slower. Such a timescale-invariant recognition is essential under natural conditions, because grasshoppers do not thermoregulate; the call of a sender sitting in the shade will be slower than that of a grasshopper in the sun. Our results show that timescale-invariant stimulus recognition can be implemented at the single-cell level without directly calculating the ratio between pulse and interpulse durations

Control systém of matrix display

Obsahem této bakalářské práce je návrh a realizace programového vybavení pro maticovou zobrazovací jednotku BUSE na základě Raspberry Pi. Maticový displej byl nejprve oživen, neboť při pokusu o zprovoznění vykazoval známky nefunkčnosti. Došlo k výměně několika elektronických součástek. Řídicí systém umožňuje návrhy obrazovek a animací pro maticovou jednotku a jejich následné vykreslení na displej. Návrh obrazovek je umožněn přes grafický prvek bitmapy. V této práci byly vytvořeny celkem tři programy. Řídicí program na PC, program na mikrokontrolér ATmega128A, který z přijatých dat vykresluje obrazovky na displej, a program do mikropočítače Raspberry Pi, který se stará o přeposílání dat mezi mikrokontrolérem a PC.The content of this thesis is to design and implement control system for a matrix display BUSE using Raspberry Pi. At first the matrix display was revived because after several attemps of commissioning it seemed to be broken and there were some electrical components that needed to be replaced. The control system allows to design screens and animations for matrix display through graphical element called bitmap. The thesis contains creation of three programs. The control program running on PC, program for microcontroler ATmega128A which displays screens on BUSE panel and program for Raspberry PI which resends data between microcontroller and computer.

Defects classification

Práce se zabývá návrhem a vytvořením klasifikátorů defektů vad nalezených na pásech kontinuální výroby. Nejprve se práce věnuje rešerši používaných metod pro klasifikaci obrazu a analýze vlastností dodaných vzorů vad na textilii. Poté je popsáno vytvořené rozhraní klasifikátoru a vytvořené grafické rozhraní pro práci s klasifikátorem. Závěrečná část práce je věnována implementaci klasifikátorů a zhodnocení jejich spolehlivosti na dodaných vzorcích vad.The thesis deals with a concept and creation of classifiers of defects found on continuous production lines. The first part presents an overview of methods used for image classification and a analysis of defects. The main part of the thesis consist of a description of created classifier interface and graphical user interface for classifier. The last part sums up reliability of each implemented classifer.

Self-compassion and its role in emotion regulation, maintaining mental health and well-being

Self-compassion and its role in emotion regulation, maintaining mental health and well-being PhDr. Jan Benda Supervisor: prof. PhDr. Jiří Šípek, CSc., Ph.D. Abstract Background. Frequent comorbidity of mental disorders together with the latest findings in neurobiology have been drawing attention of health professionals over the past years to so- called transdiagnostic factors, including, but not limited to difficulties in emotion regulation and self-compassion. It seems that these factors play a significant role in the etiology of many mental disorders as well as in the maintenance of mental health and well-being. Objectives. The aim of this thesis was to theoretically discuss and scientifically verify the expected relationship between parental emotional warmth in childhood, self-compassion and emotion regulation. Sample and procedure. 440 adult respondents (141 men and 299 women) completed the questionnaire "My Memories of Upbringing"- Short Form (s-EMBU), the Difficulties in Emotion Regulation Scale-Short Form (DERS-SF-CZ) and the Self-Compassion Scale (SCS-CZ) together with several demographic questions in an online survey. Statistical analysis. Descriptive statistics and the Pearson's correlation coefficients were calculated using IBM SPSS Statistics-23 software. The effect of gender and education on...Soucit se sebou a jeho role v regulaci emocí, udržování duševního zdraví a osobní pohody PhDr. Jan Benda Vedoucí práce: prof. PhDr. Jiří Šípek, CSc., Ph.D. Abstrakt Východiska. Častá komorbidita psychických poruch stejně jako nejnovější poznatky neurobiologie obracejí v posledních letech pozornost odborníků k takzvaným transdiagnostickým faktorům, mimo jiné i k potížím v regulaci emocí a k soucitu se sebou. Zdá se, že tyto faktory hrají důležitou roli v etiologii řady duševních poruch i v udržování duševního zdraví a osobní pohody. Cíle. Cílem této práce bylo teoreticky prodiskutovat a následně výzkumně prověřit předpokládaný vztah mezi vřelostí rodičů v dětství, soucitem se sebou a regulací emocí. Soubor a procedura. 440 dospělých respondentů (141 mužů a 299 žen) vyplnilo v online šetření Zkrácený dotazník zapamatovaného rodičovského chování (s-EMBU), krátkou formu Škály potíží v regulaci emocí (DERS-SF-CZ) a Škálu soucitu se sebou (SCS-CZ) spolu s několika demografickými otázkami. Statistická analýza. S využitím programu IBM SPSS Statistics-23 byly provedeny výpočty deskriptivní statistiky a Pearsonových korelačních koeficientů. Vliv pohlaví a vzdělání na skóry klíčových proměnných byl testován pomocí dvoucestné vícerozměrné analýzy rozptylu (MANOVA). Rozdíly ve velikosti korelací u mužů a žen jsme...Katedra psychologieDepartment of PsychologyFaculty of ArtsFilozofická fakult

Remnants of an ancient deltaretrovirus in the genomes of horseshoe aats (Rhinolophidae)

Endogenous retrovirus (ERV) sequences provide a rich source of information about the long-term interactions between retroviruses and their hosts. However, most ERVs are derived from a subset of retrovirus groups, while ERVs derived from certain other groups remain extremely rare. In particular, only a single ERV sequence has been identified that shows evidence of being related to an ancient , despite the large number of vertebrate genome sequences now available. In this report, we identify a second example of an ERV sequence putatively derived from a past deltaretroviral infection, in the genomes of several species of horseshoe bats (Rhinolophidae). This sequence represents a fragment of viral genome derived from a single integration. The time of the integration was estimated to be 11-19 million years ago. This finding, together with the previously identified endogenous in long-fingered bats (Miniopteridae), suggest a close association of bats with ancient deltaretroviruses